From: "Eric D. Mudama" <edmudama@bounceswoosh.org>
To: Stan Hoeppner <stan@hardwarefreak.com>
Cc: maurice <mhilarius@gmail.com>,
Roberto Spadim <roberto@spadim.com.br>,
linux-raid@vger.kernel.org
Subject: Re: SSD - TRIM command
Date: Wed, 9 Feb 2011 02:05:22 -0700 [thread overview]
Message-ID: <20110209090522.GA8632@bounceswoosh.org> (raw)
In-Reply-To: <4D5245DF.4020401@hardwarefreak.com>
On Wed, Feb 9 at 1:44, Stan Hoeppner wrote:
>maurice put forth on 2/8/2011 11:37 AM:
>> On 2/7/2011 1:07 PM, Roberto Spadim wrote:
>>> hi guys, could md send TRIM command to ssd? using ext4 discart mount option?
>>> if i mix ssd and hd, could this TRIM be rewrite to non TRIM compatible disks?
>>>
>> I have read that using md with SSDs is not a great idea:
>> Form the Fedora 14 documentation:
>
>Using any RAID level but pure striping with SSDs is a bad idea, for the exact
>reason in that documentation: excessive writes.
If I mirror two SSDs, and write 1 unit of data to the mirror, each
element of the mirror should see 1 unit of write. How does this
perform excessive writes, compared to the same workload applied to a
single SSD?
I agree that in aggregate we've now done 2 units worth of writes,
however, in a mirror case, we're protecting against both whole-device
failure and single-sector failure modes, so hardly seems like a bad
idea in all applications.
--
Eric D. Mudama
edmudama@bounceswoosh.org
next prev parent reply other threads:[~2011-02-09 9:05 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-07 20:07 SSD - TRIM command Roberto Spadim
2011-02-08 17:37 ` maurice
2011-02-08 18:31 ` Roberto Spadim
[not found] ` <AANLkTik5SumqyTN5LZVntna8nunvPe7v38TSFf9eCfcU@mail.gmail.com>
2011-02-08 20:50 ` Roberto Spadim
2011-02-08 21:18 ` maurice
2011-02-08 21:33 ` Roberto Spadim
2011-02-09 7:44 ` Stan Hoeppner
2011-02-09 9:05 ` Eric D. Mudama [this message]
2011-02-09 15:45 ` Chris Worley
2011-02-09 13:29 ` David Brown
2011-02-09 14:39 ` Roberto Spadim
2011-02-09 15:00 ` Scott E. Armitage
2011-02-09 15:52 ` Chris Worley
2011-02-09 19:15 ` Doug Dumitru
2011-02-09 19:22 ` Roberto Spadim
2011-02-09 16:19 ` Eric D. Mudama
2011-02-09 16:28 ` Scott E. Armitage
2011-02-09 17:17 ` Eric D. Mudama
2011-02-09 18:18 ` Roberto Spadim
2011-02-09 18:24 ` Piergiorgio Sartor
2011-02-09 18:30 ` Roberto Spadim
2011-02-09 18:38 ` Piergiorgio Sartor
2011-02-09 18:46 ` Roberto Spadim
2011-02-09 18:52 ` Roberto Spadim
2011-02-09 19:13 ` Piergiorgio Sartor
2011-02-09 19:16 ` Roberto Spadim
2011-02-09 19:21 ` Piergiorgio Sartor
2011-02-09 19:27 ` Roberto Spadim
2011-02-21 18:24 ` Phillip Susi
2011-02-21 18:30 ` Roberto Spadim
2011-02-09 15:49 ` David Brown
2011-02-21 18:20 ` Phillip Susi
2011-02-21 18:25 ` Roberto Spadim
2011-02-21 18:34 ` Phillip Susi
2011-02-21 18:48 ` Roberto Spadim
2011-02-21 18:51 ` Mathias Burén
2011-02-21 19:32 ` Roberto Spadim
2011-02-21 19:38 ` Mathias Burén
2011-02-21 19:39 ` Mathias Burén
2011-02-21 19:43 ` Roberto Spadim
2011-02-21 20:45 ` Phillip Susi
2011-02-21 19:39 ` Roberto Spadim
2011-02-21 19:51 ` Doug Dumitru
2011-02-21 19:57 ` Roberto Spadim
2011-02-21 20:47 ` Phillip Susi
2011-02-21 21:02 ` Mathias Burén
2011-02-21 22:52 ` Roberto Spadim
2011-02-21 23:41 ` Mathias Burén
2011-02-21 23:42 ` Mathias Burén
2011-02-21 23:52 ` Roberto Spadim
2011-02-22 0:25 ` Mathias Burén
2011-02-22 0:30 ` Brendan Conoboy
2011-02-22 0:36 ` Eric D. Mudama
2011-02-22 1:46 ` Roberto Spadim
2011-02-22 1:52 ` Mathias Burén
2011-02-22 1:55 ` Roberto Spadim
2011-02-22 2:01 ` Eric D. Mudama
2011-02-22 2:02 ` Mikael Abrahamsson
2011-02-22 2:22 ` Guy Watkins
2011-02-22 2:27 ` Roberto Spadim
2011-02-22 3:45 ` NeilBrown
2011-02-22 4:37 ` Roberto Spadim
2011-02-22 2:38 ` Phillip Susi
2011-02-22 3:29 ` Roberto Spadim
2011-02-22 3:42 ` Roberto Spadim
2011-02-22 4:04 ` Phillip Susi
2011-02-22 4:30 ` Roberto Spadim
2011-02-22 14:45 ` Phillip Susi
2011-02-22 17:15 ` Roberto Spadim
2011-02-22 0:32 ` Eric D. Mudama
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